12 



BULLETIN 951, U. S. DEPAKTMENT OF AGRICULTURE. 



being located near the top and in the center of the room. The charts 

 taken from tlie recorders are examined and any variations in tem- 

 perature beyond the prescribed limits are noted with the time at 

 which the variations occurred. With these data at hand it is nearly 

 a,lways possible to find the cause of an excessive variation in tem- 



FiG. 9. — The temperature-control boards used by the Biochemic Division. 



perature and also to fix the responsibility, if any is due. The mere 

 fact that a permanent, continuous, and exact record is kept of the 

 temperature conditions inside the incubator room is a stimulus to 

 those in charge to do their best to maintain the conditions desired. 



